Barnstable, MA water hardness

Tap water hardness
27mg/L
1.6gpg
Soft

Reported by Centerville Osterville Marstons Mills WD · August 2025

MA typical
38 mg/L
EPA health violations since 2016
0
Data
Utility report

Barnstable water measures 27 mg/L (1.6 gpg) of hardness, soft by USGS standards. The number comes from Centerville Osterville Marstons Mills WD, dated August 2025.

Barnstable on the hardness scale, with nearby cities
060120180240300360+MA typical 38Fall River: 8 mg/LFall River 8New Bedford: 18 mg/LNew Bedford 18Plymouth: 26 mg/LPlymouth 26East Falmouth: 30 mg/LEast Falmouth 30Kingston: 39 mg/LKingston 39Middleborough Center: 42 mg/LMiddleborough Center 42Somerset: 45 mg/LSomerset 45Taunton: 47 mg/LTaunton 47Bridgewater: 62 mg/LBridgewater 62Scituate: 68 mg/LScituate 68Barnstable 27mg/L as calcium carbonate060120180240300360+MA 38Fall River: 8 mg/LFall River 8New Bedford: 18 mg/LNew Bedford 18Plymouth: 26 mg/LPlymouth 26East Falmouth: 30 mg/LEast Falmo. 30Kingston: 39 mg/LKingston 39Middleborough Center: 42 mg/LMiddleboro. 4227 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

At 27 mg/L, Barnstable is 11 mg/L below the typical Massachusetts figure of 38. Of the 10 nearest cities we track, 3 have softer water and 7 have harder. The range nearby runs from 8 mg/L in Fall River to 68 in Scituate.

What 27 mg/L means at home

Soap and shampoo lather with very little product. Kettles and showerheads stay mostly free of white crust.

Some people notice that soap feels slow to rinse off in soft water. That slippery feel is normal and harmless.

Hardness is not a health problem, and EPA sets no limit for it. It is a matter of scale and soap.

What to do about it

Nothing, as far as hardness goes. At 27 mg/L a softener would have almost nothing to remove.

Carbon filter

If the water tastes of chlorine, a pitcher or faucet carbon filter takes care of that. It does not change hardness.

EPA record for Barnstable's water system

Centerville Osterville Marstons Mills WD · PWSID MA4020002

No health-based violations since 2016

Serves about 50,000 people from groundwater.

Health-based
0
Monitoring or reporting
31
Open now
0

Health-based means a contaminant above its legal limit or a missed treatment step. Monitoring and reporting violations are late or missing tests and notices. Source: EPA ECHO, 2026Q3 export, violations with periods starting 2016 or later. Full EPA record.

Questions

Is Barnstable water hard?

No. It measures about 27 mg/L (1.6 grains per gallon), which the USGS classes as soft.

What is the water hardness in Barnstable in grains per gallon?

About 1.6 gpg. One grain per gallon equals 17.1 mg/L, so 27 mg/L divided by 17.1 gives 1.6.

Has the Barnstable water system had EPA violations?

EPA records show no health-based violations for Centerville Osterville Marstons Mills WD since 2016. There were also 31 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 104 cities in Massachusetts

Hardness data: TapWaterData US Water Hardness (utility report, August 4, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.